Effects of some methacrylate monomers used as liquid component on tensile and flexural strengths of poly(methylmethacrylate) denture base resin

Abstract

The present study was conducted to observe the effect of different monomers on tensile and flexural strengths of poly(methyl methacrylate) (PMMA) denture base resin when they were used as a liquid component. A conventional heat cured denture base polymer powder was mixed with ethyl, isobutyl and tert-butyl methacrylate monomers respectively. After the polymerisation process was completed, the tensile and flexural strengths of these specimens were compared with those of PMMA resin specimens polymerised with methylmethacrylate monomer (MMA). Tensile specimens were prepared in a dumbbell shape using a stainless steel mould constructed according to ASTM D638M-91a. Rectangular flexural specimens were prepared as designated in ASTM D790M-92. Each group was subjected to tensile strength and flexural strength tests using a universal testing machine at a crosshead speed of 50 mm min−1. In addition to mechanical tests, the structural change in the acrylic resin specimens prepared with different monomers was observed using a Fourier transform infrared spectrometer with attenuated total reflectance unit. The differences in the tensile strengths of all specimens were not found to be statistically significant (p>0·05), whereas the flexural strengths showed statistical differences among the groups tested (p<0·05). In the results of the tests performed, it was reached that the flexural and tensile strengths of acrylic resins obtained by various methacrylate monomers were different. It can be said that these acrylic resins can be used for various aims in different fields and in the dentistry field.